Calendar Item Invite Issue After Migrating from Google Calendar to iCloud Calendar

I recently migrated my Google Calendar to my iCloud account, and everything is working well, except for one pesky issue: My iCloud account username is my gmail address, and every calendar invite I receive goes to my Google Calendar instead of my iCloud calendar. Does anyone know how to fix this?

I have seen numerous posts online about the opposite issue, but I haven't been able to find a solution for this problem. (It looks like someone asked about the same issue here, but there were no responses to that thread.) Thanks for your help!